The invention relates to machine maintenance, and more particularly, to a technique for increasing the prediction accuracy for hardware replacement before hardware failure.
As electronic imaging machines such as copiers and printers become more complex and versatile in operation with greater speed and copy output required, there is a greater demand for higher performance and reliability. A suitable control must be able to not only coordinate the operation of the various components of the machine but be able to internally diagnose and monitor machine operation and provide suitable data and service prompts for routine and orderly component replacement, maintenance, and repair without costly and unexpected machine break downs. In complex machines, the challenge to avoid time consuming and unscheduled component replacement and maintenance becomes even more critical.
In the prior art, attempts to predict needed machine maintenance and component replacement usually include counters to record machine volume, such as the number of images projected or the number of copy sheets processed. A service representative routinely monitors the machine volume to predict the need for component replacement such as the need to replace the photoreceptor, fuser rolls, or the development system after a given number of copy sheets processed.
A difficulty with the prior art systems is that mere image counts or copy sheet counts are often an unreliable predictor of component wear because of sizes and types of copy sheets. For example, a machine primarly processing a first size copy sheet, for example, 81/2 by 11 sheets will generally require component replacement at certain copy sheet counts for the various components. On the other hand, the same machine primarily processing a second size copy sheet, for example, 17 by 11 sheets, will generally require component replacement at different copy sheet counts. The reason is that 17 by 11 sheets, in the long run, usually inflict more wear on system components than an 81/2 by 11 sheet. In addition, the specific count, indicating the need for component replacement, generally differs for each component in the machine. The ability to accurately predict wear of many components thus becomes even more difficult in machines adapted to process many different sizes as well as types of copy sheets.
It would be desirable, therefore, to be able to be able to accurately predict the wear of various components in a machine that processes a wide variety of copy sheets. It is an object, therefore, of the present invention to provide a technique to predict component wear based upon a consideration of the size or type of copy sheet processed. Another object of the present invention is to provide a technique to normalize processed sheet counts in a machine to a single standard to account for variations in the copy sheets processed. Other advantages of the present invention will become apparent as the following description proceeds, and the features characterizing the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.